Field of the Invention (Technical Field)
An embodiment of the present invention relates to a compressor equipped emissions free dehydrator which can preferably capture at least substantially all hydrocarbon liquids and vapors produced by the process of removing water vapor from a flowing gas stream.
Description of Related Art
A conventional dehydrator contacts in a pressure vessel (absorber) the flowing gas stream. Normally, triethylene glycol is used as the contact medium. The triethylene glycol absorbs water vapor contained in the gas as well as some of the gas aromatics, (such as benzene, ethylbenzene, toluene, and xylenes commonly referred to as BTEX). The wet glycol (commonly called rich glycol) exits the absorber and is sent to a heated vessel (reboiler) where the glycol is heated to approximately 400 degrees F. Heating the glycol drives off the absorbed water as well as the absorbed BTEX (BTEX is a hazardous waste that has been proven to be carcinogenic). The heated stream of steam, BTEX, and other hydrocarbons exits the reboiler at approximately atmospheric pressure and 400 degrees F. To prevent atmospheric pollution, the heated stream must be processed to capture all the BTEX and any other hydrocarbon products the stream might contain.
Although BTEX is the major concern as a gas dehydration hazardous waste, there are other hazardous wastes such as methane gas (which may contain other hydrocarbon components) produced by the dehydration process. Most methane produced by gas dehydration is caused by glycol pumps, gas stripping of the rich glycol, and flashing as the rich glycol is released from high pressure to atmospheric pressure. There is thus a present need for a method, system, and apparatus which can capture the emissions and compress them to in excess of 200 pounds per square inch gauge pressure (“psig”).
Objects, advantages and novel features, and further scope of applicability of the present invention will be set forth in part in the detailed description to follow, taken in conjunction with the accompanying drawings, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention.